Does this CFS soffit framing make sense? 2

[Structintern3]

Hey Guys,

I'm framing a soffit out of exclusively cold-formed steel(studs and tracks). I'm attaching the soffit to a combination of a steel beam and a concrete curb above the beam. I've provided a sketch of my initial markup for framing it, does this make sense to you guys? If it doesn't, what issues are you seeing? Again, this is a nonstructural soffit that is pretty low weight.

 

[sticksandtriangles]

Looks good to me. Only item I noticed is that the diagonal gets a bit tricky as you have drawn it, it would require the person in the field to trim the flange as it overlaps with either the horizontal/vertical stud.

I like to add diagonals on any CFS boxes as you have shown over ~1'-0" just because getting a moment connection in a CFS screwed cnx can be tough to justify.

S&T -

http://www.re-tug.com

 

[milkshakelake]

The main vertical load is on the box beam. The two attachments above are taking axial tension/compression forces. The load path makes sense.

Edit: Didn't notice the concrete below. That would take the vertical loads.

 

[DaveAtkins]

It looks good to me, except for the slip track at the bottom of the wide flange beam. The weight of the soffit will be supported at the concrete curb, and the CFS box header only takes lateral load. You should not have a slip track at the bottom of the wide flange beam, because the entire soffit will ride up and down with the beam. There should be a slip track at the head of the window, provided by the window manufacturer. You probably don't need a box header, since everything is supported at the curb above.

DaveAtkins

 

[DaveAtkins]

Addendum to my earlier post - if you eliminate the box header, you still need lateral support for the soffit framing at the bottom of the wide flange beam. You could run a horizontal CFS member from the soffit framing to the underside of the bottom flange, and use a clip to attach the member to the flange.

DaveAtkins